What I do - I start computer unconnected to Internet, in Task manager I close all that I can not push not to start at start up - like Microsoft team. I open Vegas project which has 452 clips. On my machine with 32Gb RAM Vegas at the beginning occupies 31Gb. If I start rendering at this moment, it crash with Out of memory error. In the task manager I wait - relatively long time - 10-20 minutes - when Vegas application activity with CPU, GPU, HDD become close to 0. At this moment RAM usage drops to about 21Gb. If you do something like selecting project area, the activity may rise again. You need to wait again. If I start rendering when activity gone - rendering goes without problem.